/*
 *  Copyright 2009 Lucas Nazário dos Santos
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package net.sourceforge.retriever.fetcher.dns;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class JavaDNSResolver implements DNSResolver {


	public String getIP(final String url) {
		final String host = this.getHost(url);
		try {
			return InetAddress.getByName(host).getHostAddress();
		} catch (final UnknownHostException e) {
			return host;
		}
	}

	private String getHost(final String url) {
		final int firstIndexOf = url.indexOf("://") + 3;
		int lastIndexOf = url.indexOf("/", firstIndexOf);
		if (lastIndexOf == -1) lastIndexOf = url.length();

		String host = url.substring(firstIndexOf, lastIndexOf);

		final int indexOfAt = host.indexOf("@");
		if (indexOfAt > -1) host = host.substring(indexOfAt + 1);
		
		final int indexOfPort = host.indexOf(":");
		if (indexOfPort > -1) host = host.substring(0, indexOfPort);

		return host;
	}
}